Preparation of 2-fluoronitrobenzene

Abstract

An improved process for preparing 2-fluoronitrobenzene by reacting 2-chloronitrobenzene with ultra-fine particulate potassium fluoride in tetramethylene sulfone with a macrocyclic ether or a quaternary ammonium halide catalyst. 2-fluoronitrobenzene is an intermediate useful in the preparation of certain known herbicides.

I claim: 
     
       1. A process for preparing 2-fluoronitrobenzene which comprises heating a mixture of 2-chloronitrobenzene potassium fluoride of particle size 1-20 microns and a catalyst in sulfolane for 2-8 hours at 240°-250° C wherein the molar ratio of 2-chloronitrobenzene to potassium fluoride to sulfolane is 1 : 1.1-1.5 : 0.3-1.0. 
     
     
       2. The process of claim 1 wherein the reaction is carried out at 240°-242° C and the molar ratio of 2-chloronitrobenzene to potassium fluoride to sulfolane is 1: 1.1-1.5 : 0.9-1.0. 
     
     
       3. The process of claim 1 wherein the catalyst is selected from the group consisting of macrocyclic ethers and quaternary ammonium halides. 
     
     
       4. The process of claim 2 wherein the catalyst is selected from the group consisting of macrocyclic ethers and quaternary ammonium halides. 
     
     
       5. The process of claim 4 wherein the catalyst is 1,4,7,10,13,16-hexaoxacyclooctadecane and the molar ratio of 2-chloronitrobenzene to catalyst is 1 : 0.001-0.01. 
     
     
       6. The process of claim 5 wherein the reaction is carried out at 240°-242° C. 
     
     
       7. The process of claim 5 wherein the molar ratio of 2-chloronitrobenzene to catalyst is 1 : 0.002-0.004. 
     
     
       8. The process of claim 7 wherein the reaction is carried out at 240°-242° C. 
     
     
       9. The process of claim 4 wherein the catalyst is a quaternary ammonium halide and the molar ratio of 2-chloronitrobennzene to catalyst is 1 : 0.01-0.05. 
     
     
       10. The process of claim 9 wherein the catalyst is selected from the group consisting of tetrabutylammonium chloride, benzyltrimethylammonium fluoride, or benzyltriethylammonium chloride. 
     
     
       11. The process of claim 10 wherein the reaction is carried out at 240°-242° C. 
     
     
       12. The process of claim 10 wherein the molar ratio of 2-chloronitrobenzene to catalyst is 1 : 0.02-0.03. 
     
     
       13. The process of claim 12 wherein the reaction is carried out at 240°-242° C.